Weather strip, method of manufacturing the same, and mold used in the same method

ABSTRACT

The core mold in the molding device ( 51 ) for forming the molded member ( 4 ) of the weather strip ( 1 ) is provided with a center core ( 61 ) having a center core body ( 63 ), and a side core ( 62 ) having a pair of side core bodies ( 66 L,  66 R). The base bottom portion ( 21 ) of the molded member ( 4 ) is made so that a center slit ( 33 ) having substantially an H-shape, a pair of slide slits ( 32 L,  32 R), and slit-less bridge portion ( 34 ). In order to open the molds, the side core ( 62 ) is slid, and the center core body ( 63 ) is thereby separated from the side core bodies ( 66 L,  66 R). The center core body ( 63 ) is thereby withdrawn from the weather strip ( 1 ), and the side core bodies ( 66 L,  66 R) thereafter are withdrawn.

The present application is based on Japanese Patent Applications Nos.2003-164598 and 2003-433457, which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a weather strip, a method ofmanufacturing the same, and a molding device used in the same method.

2. Related Art

The manufacturing of a related art weather strip of this kind has beendone by a known extrusion molding method in which an extruded member isformed in an elongated state. A molded member is then formed in acontinuously connected state with respect to an end surface of theextruded member with a front section of the extruded member set in amolding device used to form the molded member.

The molding device used to continuously form the molded member includesa fixed mold, a plurality of movable molds and core molds. The coremolds include core bodies for forming hollow portion, and core-extendedplates extending from the core bodies. In order to form a molded member,an extruded member formed in advance by a known extrusion molding methodis set first with each mold opened, in such a manner that an end portionof the extruded member is fitted in an end portion of the core body, theextruded member being thus fixed in the molding device. Next, each moldis disposed in a predetermined position, and the molding device isclosed. At this point in time, molded member forming cavities are formedby the molds. Unvulcanized rubber is then injected into the cavities viaa gate (not shown) and the like so as to fill the cavities therewith.The unvulcanized rubber is thereafter vulcanized. Each mold is opened,and core molds and vulcanized rubber (precursor of a molded member)combined together are removed. At this time, slits are formed in theprecursor of the molded member owing to the existence of thecore-extended plates.

When the core bodies are taken out from the slits, a hollow-carryingprecursor of the molded member is obtained. The opposed openings of theslits are then joined together at a plurality of positions with anadhesive to obtain a molded member. In short, a weather strip in whichthis molded member and extruded member are combined together is obtained(refer to, for example, Japanese unexamined Patent Publication No.JP-S58-205749A).

In order to try to form the hollow portion in the whole longitudinalregion of the molded member, the core body is necessarily provided overthe whole longitudinal region of the molded member. When the easiness ofthe withdrawal of the core body is taken into consideration, it isdesirable that the slits be also formed in substantially the wholelongitudinal region of the molded member.

However, the slit becomes long in this case, so that it becomesnecessary in many positions to bond the slit defining portions togetherafter the core bodies are taken out. This causes the possibility thatthe operation man-hour and manufacturing cost necessarily increase toarise.

Since the slits are closed with an adhesive, the molded member isnecessarily deformed in its width reducing direction. Therefore, it isnecessary to design a product and molds with a deformation margin of themolded member estimated, and there is the possibility that thisincreases complexity and man-hour of the designing operation.

SUMMARY OF THE INVENTION

The present invention has been made so as to solve these problems, andan object of the invention is to provide a weather strip having a moldedmember and capable of suppressing an increase in the man-hour of theweather strip manufacturing operation, the man-hour of the product andmold designing operation, and the weather strip manufacturing cost, and,moreover, a weather strip capable of greatly improving the workefficiency; a method of manufacturing the same; and a molding deviceused to practice the same method.

The means suitable to attain the above object will now be itemized anddescribed. The operation and effects peculiar to the respective meanswill be added as necessary.

(1) The invention provides a method of manufacturing weather strips,adapted to manufacture a weather strip having a molded member which isprovided with a base bottom portion, and a seal portion projecting fromthe base bottom portion and forming a hollow portion therein, a cavitybeing formed by a molding device in which at least a core mold forforming a hollow portion is provided, an elastic material in aplasticized state being injected into the cavity, the cavity being thusfilled with this material, the same material being then solidified, atleast three longitudinally extending slits, and bridge portion formedbetween the slits being formed in consequence in and on the base bottomportion, the molding device being opened, the core mold being removedfrom the three slits to obtain the molded member in which the hollowportion is formed, characterized in that the core mold is provided witha center core having a center core body, and a center extension plateextending from the center core body, and side cores having a pair ofside core bodies connected to the portions of the center core which arelongitudinally on both sides of the weather strip, and side extensionplates extending from the side core bodies, the three slits including acenter slit for withdrawing the center body therefrom, and a pair ofside slits for withdrawing the side core bodies therefrom, the centerslit including a first slit part the length of which is equal to orsubstantially equal to that in the longitudinal direction of the weatherstrip of the center core body, and second slit parts extending in thedirection in which the second slit parts intersect with the first slitpart, the core mold removing operation being carried out by extractingthe center core body from the center slit, and thereafter withdrawingthe side core bodies from the side slits.

According to the invention, the core mold is divided into a center coreand a pair of side cores, so that the slits formed by the core moldbecome short divided slits, this enabling bridge portion to be formedamong the slits. Therefore, unlike a related art weather strip in whichthe slit-defining portions have to be closed and bonded together after adie forming operation is carried out, the weather strip according to thepresent invention does not have to carry out a bonding operation owingto the existence of the bridge portion. Moreover, it is not necessary ina designing operation to estimate the size of a deformation margin forclosing the slit-defining portions. Therefore, it is possible to holddown an increase in the designing man-hour and operation man-hour, andan increase in the manufacturing cost. Furthermore, since the slits areformed in the base bottom portion unlike the case where the slits areformed in a seal portion, the spoiling of the rigidity of the sealportion and a decrease in the sealability thereof due to the slits canbe prevented. Also, the second slit parts are provided in the centerslit, the first slit part can be opened greatly with ease in thewidthwise direction thereof. Accordingly, the withdrawing of the centercore body when the core mold is released can be carried out easily. Inaddition, when the center core is taken out first, a part of the weatherstrip is unfixed. Therefore, when the side core bodies are withdrawn,the weather strip is deformed and relatively moved easily with respectto the side core bodies, and the withdrawing of the side core bodies canalso be done easily. For example, when the molding device is formed sothat the center core body only is withdrawn automatically at the time ofopening of the mold, the core metal removing operation to be thereaftercarried out includes only a side core body withdrawing operation. Theside core body withdrawing operation can also be carried out easily. Asa result, the work efficiency can be greatly improved.

(2) In the invention, the two side extension plates constituting theside core may be joined together by a connecting portion, the core moldremoving operation being carried out by sliding the side cores in theside extension plate extending direction, the side core bodies beingthereby separated relatively from the center core body, which is therebywithdrawn from the hollow portion of the molded body.

According to the above construction, the side cores are slid only, andthe center core body is separated relatively from a position between theside core bodies. During this time, the molded member is slid with theside core bodies, so that the center core body is necessarily withdrawncomparatively easily. Moreover, since the two side extension plates arejoined together in one body by the connecting portion, the withdrawal ofthe center core body is completed by one sliding operation. This enablesthe work efficiency to be further improved.

(3) In the invention, each of the side slits may include a main slitpart formed by the side extension plates, and extension slit partsprovided so as to extend from ends of the main slit part in thelongitudinal direction of the weather strip and formed by a mold partdifferent from the side extension plates.

According to the above construction, the side slits have extension slitparts, and the length of the extension slit parts are therefore largerthan that of the main slit part formed by the side extension plates.Accordingly, in order to withdraw the side core bodies from theabove-mentioned slits, the side extension plates are moved toward oneend in the side slits even though the total length of the side slits issmaller than the length with respect to the longitudinal direction ofthe weather strip of the side core bodies, and the end portions of theside core bodies are withdrawn from the other end in the side slits.This enables the side core bodies to be withdrawn easily.

(4) In the invention, the mold part for forming the extension slit partsmay be also separated relatively from the side core bodies at the sametime that the center core body is separated relatively from the sidecore bodies and withdrawn when the molding device is opened.

According to the above construction, the relative separation of thecenter core body and side core bodies from each other and the relativeseparation of the mold part for forming the extension slit parts andside core bodies from each other are carried out at once, so that thework efficiency can be improved. When the two relative separationoperations are carried out simultaneously by sliding the side coresconnected together in one body, the work efficiency can further beimproved.

(5) In the invention, the extension slit parts of the side slits may beformed on both ends of the main slit, a molded body being set relativelymovable when the side core bodies are withdrawn from the side slits, insuch a manner that the side extension plates are made to be put into theone end side core-extended slit part.

According to the above construction, the extension slit parts of theside slits are formed at both ends of the main slit part. Therefore,when a molded body is moved with respect to the side cores after thecenter core body is withdrawn from the molded member, both of the sideextension plates smoothly enter the interior of the extension slit partson one side in the two side slits. When the end portions of the sidecore bodies are then withdrawn from the other end sides of the sideslits, the side core bodies can be withdrawn easily from the side slits.

(6) In the invention, the center slit may be formed by the centerextension plate.

According to the above construction, the center slit is formed by thecenter extension plate. Namely, another mold is not needed to form thecenter slit. Therefore, in order to withdraw the center core body, it isunnecessary to separate an additional mold therefrom since the centerslit is formed in advance. The center core body can be withdrawn by onlymoving the center core with respect to the molded member.

(7) In the invention, the second slit parts of the center slit may beformed substantially at both end portions of the first slit part thereofso as to intersect with the first slit part at right angles thereto orat substantially right angles thereto, and so as to have a lengthsubstantially equal to the width of the surface of the center core bodywhich is on the side of the base bottom portion.

According to the above construction, the second slit parts of the centerslit are formed substantially at both end portions of the first slitpart thereof so as to intersect with the first slit part at right anglesthereto or at substantially right angles thereto. Therefore, the openingof the center slit can be opened substantially rectangularly. Inaddition, the second slit parts are formed so as to have a lengthsubstantially equal to the width of the surface of the center core bodywhich is on the side of the base bottom portion. This enables the centerslit to be opened sufficiently greatly with respect to the center corebody. Accordingly, the withdrawing of the center core body can be donemore easily.

(8) In the invention, the molded member may be a member fitted in acorner portion of a door sash, the not smaller than three slits beingformed in one side of the corner portion, in an angular section of thecorner portion, and in the section of the base bottom portion whichcorrespond to the other side of the corner portion.

According to the above construction, the not smaller than three slitsare formed in one side of a corner portion of a door sash, in an angularsection of the corner portion, and in the section of the base bottomportion which correspond to the other side of the corner portion. Evenwhen the molded member is fitted in the corner portion, the shapefollow-up characteristics of the weather strip can be improved owing tothe existence of the slits formed in the corner portion of the sash.

(9) In the invention, the molded member may be made so that the moldedmember connects both ends of the extruded member, which is formedseparately therefrom, together or respective ends of a plurality ofextruded members together.

According to the above construction, the core mold can be removed easilyeven when the molded member is made so that the end portions of theextruded member, which is formed separately therefrom, are connectedtogether.

(10) In the invention, the molded member may be formed so as to beconnected to one end of the separately formed extruded member.

According to the above structure, the core mold can be removed easilyeven when the molded member is formed so as to be connected to one endof the extruded member formed separately therefrom.

(11) A weather strip provided with a molded member having a base bottomportion, and a seal portion projecting from the base bottom portion andforming a hollow portion therein, characterized in that the base bottomportion of the molded member is provided with three longitudinallyextending slits including a center slit, and two side slits made on bothsides of the center slit, bridge portion being formed among these slits,the center slit being provided with a first slit part, and second slitparts formed substantially at both ends of the first slit part so thatthe second slit parts intersect with the first slit part.

According to the above construction, the center slit is provided withsecond slit parts, so that the first slit part can be opened greatly inthe widthwise direction thereof with ease. The rigidity of the portionof the base bottom portion in which the center slit is formed becomeslower than that of the portion thereof in which the side slits areformed but an extremely large decrease in the rigidity of the formerportion of the base bottom portion can be held down owing to theexistence of the bridge portion. This enables the shape follow-upcharacteristics of the weather strip with respect to a weather stripfixing operation to be improved. Furthermore, unlike a related artweather strip in which the slits have to be closed and bonded after amolding operation finishes, the weather strip according to the presentinvention does not need to be subjected to a slit bonding operation. Noris it necessary when the weather strip is designed, to estimate thesizes of a deformation margin for closing the slits. Therefore, anincrease in the operation man-hour, designing man-hour and manufacturingcost can be held down. As a result, the work efficiency can be greatlyimproved.

(12) In the invention, the molded member may have a curved shape so thatthe molded member is fitted in an opening portion of a vehicle or fittedin a corner portion of a circumference of a door, the center slit as awhole being formed substantially in the H-shape or substantially in theU-shape since the second slit parts are formed so as to intersect withthe first slit part at right angles thereto or at substantially rightangles thereto.

According to the above construction, the molded member has a curvedshape, so that the weather strip has excellent shape follow-upcharacteristics with respect to the operation for fixing the weatherstrip to an opening of a vehicle and a corner portion of a circumferenceof a door. The center slit as a whole is formed substantially in theH-shape or substantially in the U-shape. When the center slit is formedsubstantially in the H-shape, the stress concentration in the widthwisedirection of the weather strip can be prevented. When the center slit isformed substantially in the U-shape, the rigidity of the seal portion ofthe weather strip or that of the portion of the weather strip which ison the widthwise opposite side of the seal portion can be secured byconversely concentrate stress in either of two widthwise directions.

(13) In the invention, the molded member may be formed substantiallylinearly, the center slit as a whole being formed substantially in theH-shape or substantially in the U-shape since the second slit parts areformed so as to intersect with the first slit part at right anglesthereto or at substantially right angles thereto.

According to the above construction, the center slit displays the sameoperation and effects as that in (12). In addition, the molded member isshaped substantially linearly, so that the weather strip is suitable tobe fixed to a substantially linear portion of an opening of a vehicleand a circumference of a door.

(14) In the invention, both ends of one extruded member or respectiveend portions of a plurality of extruded members, which are formedseparately from the molded member, may be connected to both sides of themolded member.

According to the above construction, the operation and effects describedin the above (11) to (13) are displayed even when the end portions of anextruded member, which is formed separately from the molded member areconnected to both sides of the molded member.

(15) In the invention, the molded member may be connected to the endportion of the extruded member, which is formed separately from themolded member, to form a terminal portion of the weather strip.

According to the above construction, the operation and effects describedin (11) to (13) are displayed even when the molded member constitutesthe terminal portion of the weather strip.

(16) The invention provides a molding device in which at least a coremold of a weather strip for forming molded members, each of which isprovided with a base bottom portion, and a seal portion projecting fromthe base bottom portion and forming a hollow portion therein areinstalled, the core mold being provided with a center core having acenter core body for forming the hollow portion, and a center extensionplate extending from the center core for forming a center slit in thebase bottom portion, and a side core provided with a pair of side corebodies, which are connected to both sides in the longitudinal directionof the weather strip of the hollow-forming center core, side extensionplates extending from the side core bodies for forming side slits in thebase bottom portion, and a side core having a connecting portion forconnecting the side extension plates together, the center extensionplate being provided at the portions thereof which are at both endsthereof in the longitudinal direction of the weather strip, and whichcontact the center core body, with a transverse piece portion extendingin the direction in which the transverse piece portion intersects thecenter extension plate.

According to the above construction, the core mold is divided into acenter core, and a pair of side cores, and each slit formed by the coremold therefore becomes a short divided slits, this enabling bridgeportion to be formed among the slits. Therefore, unlike a related artweather strip in which slits have to be closed and bonded together aftera die forming operation finishes, the weather strip according to thepresent invention does not need to carry out a bonding operation owingto the existence of the bridge portion. Moreover, when the mold isdesigned, it is not necessary to estimate the sizes of a deformationmargin for closing the slits. Accordingly, an increase in the operationman-hour, designing man-hour and manufacturing cost can be held down.Furthermore, since the center extension plate is provided with atransverse piece portion, second slit parts extending in the directionin which the second slit parts intersect with the first slit part owingto the transverse piece portion are formed, and the center slit can beopened widthwise greatly with ease. Therefore, when the core mold isremoved, the withdrawal of the center core body can be carried outeasily. For example, when the easily removable center core is taken outfirst, a part of the weather strip is unfixed. At the time of thewithdrawal of the side core bodies to be carried out thereafter, adeformation movement of the weather strip with respect to the side corebodies is made easily, and the withdrawal of the side core bodies canalso be done easily. When the mold is formed so that the center coreonly is withdrawn automatically from the hollow portion in accordancewith the mold opening operation, a core mold withdrawing operation to bethereafter carried out may be executed by the step of withdrawing sidecore bodies only. This operation can also be carried out easily. As aresult, the work efficiency can be improved greatly.

(17) In the invention, the molding device may be provided with endportions in the longitudinal direction of the weather strip of the sideextension plates, and projections for elongating the side slits so thatthe projections come into close contact with the side core bodies, theprojections being provided in a mold part different from the side cores.

According to the above construction, the side slits are formed longerowing to the projections than the slits formed by the side extensionplates. When the projections are separated relatively from the side corebodies in advance, the movement of the side cores with respect to thelongitudinal direction of the weather strip is made easily. Therefore,in order to withdraw the side core bodies from the side slits, the sideextension plates are brought close to one end side in the interior ofthe side slits even though the total length of the side slits is smallerthan the length in the longitudinal direction of the weather strip ofthe side core bodies, and the end portions of the side core bodies arewithdrawn from the other end side in the interior of the side slits.This enables the side core bodies to be withdrawn easily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing for describing the removal of the weather strip fromthe core mold in the first embodiment;

FIG. 2 is a schematic drawing describing a schematic construction of theweather strip in the first embodiment;

FIG. 3 is a sectional view taken along the line III-III in FIG. 2 andshowing an extruded member;

FIG. 4 is a drawing for describing the molded member corresponding to anupper corner portion of the first embodiment;

FIG. 5 is a sectional view taken along the line V-V in FIG. 4 andshowing the molded member;

FIG. 6 is a drawing for describing the molded member viewed from theside of a fixing surface of the weather strip of the first embodiment;

FIG. 7 is a drawing showing a molding device for forming the moldedmember in the first embodiment;

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 7 anddescribing the molding device and a center core;

FIG. 9 is a sectional view taken along the line IX-IX in FIG. 7 anddescribing the molding device and an orthogonal transverse piece portionof the center core;

FIG. 10 is a schematic drawing describing a schematic construction ofthe weather strip of the second embodiment;

FIG. 11A is a sectional view taken along the line XIA-XIA in FIG. 10 andshowing an extruded member, and FIG. 11B is a sectional view taken alongthe line XIB-XIB and showing a molded member;

FIG. 12 is a drawing describing the removal of the weather strip fromthe molds in the second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

A first embodiment will now be described with reference to the drawings.As shown in FIG. 2, a door weather strip (which will hereinafter bereferred to simply as “weather strip”) 1 formed out of EPDM(ethylene-propylene-diene copolymer rubber), or TPO (olefin-basedplastic elastomer) and the like is fixed to, for example, an automobiledoor so that the weather strip extends along an outer circumference ofthe door.

This weather strip 1 is provided with extruded members 2, 3 and moldedmembers (portions having dotted patterns shown in the same drawing) 4,5. The extruded members 2, 3 are formed substantially linearly (in anelongated manner). The molded members 4, 5 are formed by a predeterminedmolding device so that the molded members connect the end portions ofthe adjacent extruded members.

As shown in FIG. 3, the extruded members 2, 3 have a base bottom portion11 fixed to a sash (not shown) of an automobile door, a seal portion 13extending from the base bottom portion 11 and having a hollow portion 12therein, a lip 14 extending from a base end section of the seal portion13, and the like.

As shown in FIGS. 4 and 5, the molded members 4, 5 also have a basebottom portion 21, a hollow portion 22, a seal portion 23, and a lip 24just as the extruded members 2, 3, though the shapes of these parts ofthe molded members and molded members are different from each other. Inthis embodiment, the molded member 4 corresponding to an upper cornerportion of the weather strip is provided as shown in FIG. 6 in a basebottom portion 21 thereof with a slit 31 for the withdrawal of coremold, which will be described later.

In this embodiment, the slit 31 includes two side slits 32L, 32R, and acenter slit 33 provided therebetween. These slits 32L, 32R, 33 areformed in substantially the whole region in the longitudinal directionof the weather strip 1 of the molded member 4 so that the slits extendon substantially the same line. Between the side slits 32L, 32R andcenter slit 33, non-slit-carrying bridge portion 34 are provided.

The center slit 33 is provided with a long slit part 37 as a first slitpart extending in the longitudinal direction of the weather strip 1, andshort slit parts 38 as second slit parts formed at both ends of the longslit part and extending in the widthwise direction (direction crossingthe long slit part 37 at right angles thereof) of the weather strip 1.The center slit as a whole is formed substantially in the H-shape. Thelength of the short slit parts 38 is set substantially equal to thewidth of the surface for forming the hollow portion 22 in the basebottom portion 21. The short slit parts 38 may, of course, be formed tothe very limit width between both sides of the base bottom portion 21,i.e., to the greatest possible length. The center slit 33 may notnecessarily be formed substantially in the H-shape, and this slit mayalso be formed substantially in the U-shape. Namely, the long slit part37 may be formed in the substantially central portion in the widthwisedirection of the weather strip of the base bottom portion 21, or in thesection of the base bottom portion which is offset to one side thereofin the widthwise direction of the weather strip.

The side slits 32L, 32R are provided with main slit parts 39L, 39Rextending in the longitudinal direction of the weather strip 1, andextension slit parts 40L, 40R, 41L, 41R which extend from both ends ofthe main slit parts by a predetermined length in the longitudinaldirection of the weather strip, and which are narrower than the mainslit parts 39L, 39R. The extension slit parts 40L, 40R, 41L, 41R areprovided at the end side sections thereof with substantially circularslit end portions 42 for preventing the occurrence of cracks.

A molding device 51 for forming the molded member 4 corresponding to theupper corner portion of the weather strip 1 will now be described. FIGS.7, 8, 9 are sectional views showing the molding device 51 used to formthe molded member 4. The molding device 51 is provided, for example, alower mold 52 positioned on the lower side of FIGS. 8 and 9, an uppermold 53 positioned on the upper side of FIGS. 8 and 9, an outside upperinner-mold 54 and an outside lower inner-mold 55 which are positioned onthe outer side of the upper corner portion, and an inside upperinner-mold 56 and an inside lower inner-mold 57 which are positioned onthe inner side of the upper corner portion. Between the inside upperinner-mold 56 and inside lower inner-mold 57, a core mold is provided.The core mold includes (refer to FIG. 7) a center core 61 for use informing a substantially central hollow portion of the upper cornerportion corresponding to the molded member 4, and a side core 62 for usein forming a hollow portion continuing to both sides of the center core.

The center core 61 includes a center core body 63, and a centerextension plate 64 extending from the center core body in one body, andis held between the inside upper inner-mold 56 and inside lowerinner-mold 57. The center extension plate 64 includes a thin portion64A, and a thick portion 64B extending from the thin portion 64A in theinward direction. The center core body 63 diverges in plan toward thethin portion 64A of the center extension plate 64 and also in thelongitudinal direction of the weather strip 1 as shown in FIG. 7. Thelength in the longitudinal direction of the weather strip of the centercore body 63 is set substantially equal to that of the thin portion 64A.At both ends of the thin portions 64A, orthogonal transverse pieceportions as transverse piece portions for forming the short slit parts38 are formed so as to become integral with the thin portions. Theheight of the orthogonal transverse piece portions (having a dottedpattern shown in FIG. 9 is set substantially equal to the width of thesurface of the center core body 63 which is on the side of the basebottom portion 21.

As shown in FIG. 7, the side core 62 includes two side core bodies 66L,66R, and side extension plates 67L, 67R extending from the side corebodies 66L, 66R in an integral state with respect thereto. The length inthe longitudinal direction of the weather strip 1 of the portions of theside extension plates 67L, 67R which are connected to the side corebodies 66L, 66R is set shorter than that in the longitudinal directionof the weather strip 1 of the side bodies 66L, 66R. The side extensionplates 67L, 67R are joined together substantially in the U-shape by aconnecting portion 68 in one body. The side extension plates 67L, 67Rare formed so that the side extension plates can be slid between theinside upper inner-mold 56 and inside lower inner-mold 57 by apredetermined stroke a in the vertical direction in FIG. 7.

At a free end of the inside lower inner-mold 57, projections 69 forforming the extension slit parts 40L, 40R, 41L, 41R are formed in onebody. The projections 69 adjoin the edges of the side extension plates67L, 67R when the molds 52 to 57, 61, 62 are in a set condition. Sincethe projections 69 do not need to support the core at the free endsthereof unlike the side extension plates 67L, 67R, the thickness of theprojections is set comparatively small.

The molds 52 to 57 are provided with molding surfaces extending inconformity with an outer surface of the molded member 4. The center corebody 63 and side core bodies 66L, 66R are set in the central portion ofa space surrounded by the molds 52 to 57. These molding surfaces, i.e.outer surfaces of the center core body 63 and side core bodies 66L, 66Rform a cavity 70 for molding the molded member 4.

The method of manufacturing the weather strip 1 having theabove-described construction, and the operation and effect obtainedduring the manufacturing thereof will now be described. First, theabove-mentioned extruded members 2, 3 are obtained by using an extrusionmolding machine (not shown) and by a known extrusion molding method.Owing to this molding operation, the base bottom portion 11, sealportion 13, hollow portion 12 and lip 14 of each of the extruded members2, 3 are formed.

The molded member 4 is obtained in the following manner. First, the endportions of the extruded members 2, 3 are fitted by a predeterminedlength in the longitudinal end portions of the side core bodies 66L, 66Rwhich do not face the center core 61 with all the molds 52 to 57 opened.The molds 52 to 57, center core 61 and side core 62 are set inpredetermined positions, and closed (refer to FIG. 7). As a result, theextruded members 2, 3 are fixed with respect to the molding device 51,and the cavity 70 is formed. The length of the fitting portions of theside core bodies 66L, 66R is set slightly smaller than that of theextension slit parts 40L, 40R, 41L, 41R.

The EPDM rubber or the like in a plasticized state is then injected withthe molds in this condition from a gate (not shown) into the cavity 70to fill the same therewith. The EPDM rubber is thereafter vulcanized andsolidified. After the solidifying operation is completed, the molds arepened in order. First, the lower mold 52, upper mold 53, outside upperinner-mold 54 and outside lower inner-mold 55 are separated from themolded weather strip 1. Next, the side core 62 is slid (upward in thedrawing) with the weather strip 1 with respect to the inside upperinner-mold 56 and inside lower inner-mold 57 as shown in FIG. 1. As aresult, the weather strip 1 is separated from the inside upperinner-mold 5 and inside lower inner-mold 57, and the center core body 63in the hollow portion is removed automatically and easily from thecenter slit 33. During this time, the projections 69 of the inside lowerinner-mold 57 are also separated from the weather strip 1, so thatclearances due to the extension slit parts 40L, 40R, 41L, 41R are formedin the weather strip 1.

An operation for removing the molded member 4 from the side core bodies66L, 66R is carried out by a worker. First, for example, the portion ofthe left side (in the drawing) extruded member 2 which is in thevicinity of a joint portion thereof with respect to the molded member 4is drawn in the longitudinal direction of the left side core body 66Ltoward the left lower side, i.e., in the direction in which thementioned portion of the extruded member is separated from the side corebody 66L. As a result, the weather strip 1 is slid easily with respectto the side core 62, and the side extension plate 67L enters the rightextension slit part 40R. Owing to this operation, a left end of the leftside core body 66L comes to exist in a position slightly on the rightside a left end of the left side slit 32L. Therefore, when the pulledextruded member 2 is then drawn upward in the drawing, the left end ofthe left side core body 66L slips out easily from the side slit 32L.When the weather strip 1 is then slid rightward with respect to the sidecore body 66 and thereafter drawn upward in the drawing, the left sidecore body 66L slips out completely from the weather strip 1. The rightside core body 66R is then removed from the weather strip 1 in the sameorder as the left side core body 66L.

According to this embodiment described in detail above, the core mold isdivided into a center core 61 and two side cores 62. Therefore, theslits 32L, 32R, 33 become shorter, and slit-less portions (bridgeportion 34) can be formed on the weather strip 1. Accordingly, unlike arelated art weather strip in which slits have to be closed and bondedtogether after a die forming operation is carried out, a bondingoperation is not needed. Moreover, it is not necessary to estimateduring a designing operation the sizes of a deformation margin forclosing the slits. This enables an increase in the operation man-hour,designing man-hour and manufacturing cost to be held down.

A fear of an increase in the deformation of the molded member 4 tends toincrease in proportion to the width of the formed slit 31. However,since the width of the extension slit parts 40L, 40R, 41L, 41R is small,the suppression of the deformation of the weather strip can be effected.

Since the center slit 33 is provided with short slit parts 38, the longslit part 37 can be opened greatly in the widthwise direction with ease.Moreover, the center core body 63 is tapered. Therefore, the center corebody 63 can be withdrawn very easily from the molded member 4 by asimple operation in which the side core 62 is slid. In addition, sincethe center core body 63 is tapered, the inconvenience of interferingthereof with the side core bodies 66L, 66R to cause the same to bedamaged rarely occurs when the molding device 51 is closed. Moreover,the wear on the center core body rarely occurs. As a result, the moldingdevice 51 can be used stably for a long period of time.

When the center core body 63 is withdrawn earlier than the side corebodies 66L, 66R, a part of the weather strip is unfixed. Therefore, whenthe side core bodies 66L, 66R are withdrawn, the deformation movement ofthe weather strip 1 with respect to the side core bodies 66L, 66R comesto be easily made. Accordingly, the withdrawing of the side core bodies66L, 66R can also be done easily.

In addition, the projections 69 are provided on the inner lower mold 57.Therefore, the extension slit parts 40L, 40R, 41L, 41R are alreadyformed when the withdrawing of the side core bodies 66L, 66R from theweather strip 1 is started. Accordingly, when the side extension plates67L, 67R are inserted into the extension slit parts 40L, 40R, 41L, 41R,the weather strip 1 is slid easily with respect to the side core bodies66L, 66R, and removed easily.

When the molded weather strip 1 is removed from the molding device 51,the core mold is not removed solely therefrom. This enables a fall of acore mold and damage to the molding device 51 to be prevented.

The slit 31 is molded in the base bottom portion 21 of the molded member4. For example, when a slit is formed in the seal portion 23, therigidity of the seal portion 23 is spoiled due to the slit, and thepossibility of causing a decrease in the sealability of the seal portionoccurs. In this embodiment, a decrease in the sealability of the sealportion can be prevented.

The rigidity of the portion of the base bottom portion in which thegreatly openable center slit 33 is formed becomes lower than that of theportion thereof in which the side slits 32L, 32R are formed. Therefore,when the weather strip is fixed to a circumference of an opening, theshape follow-up characteristics thereof can be heightened even withrespect to a curved portion, such as an upper corner portion of a doorof an automobile. In the meantime, an extreme decrease in the rigiditycan be held down owing to the existence of the bridge portion 34.

The center slit 33 is formed substantially in the H-shape orsubstantially in the U-shape. When the center slit 33 is substantiallyH-shaped, the stress concentration in the widthwise direction of theweather strip can be prevented. When the center slit is substantiallyU-shaped, the stress concentration is done conversely, i.e., in eitherof the widthwise directions. This enables the rigidity of the sealportion or lip to be secured.

Since the removal of the weather strip 1 from the molding device 51 iscarried out easily as mentioned above, the work efficiency can beimproved greatly.

Second Embodiment

The second embodiment will now be described by attaching importance tothe differences between this embodiment and the first embodiment. Aweather strip 101 is provided at a longitudinal end portion thereof witha molded member 104, which is connected at one end thereof to anextruded member 102 (refer to FIG. 10). The molded member 104 is formedsubstantially linearly unlike that of the first embodiment. As shown inFIGS. 11A and 11B, the extruded member 102 is provided with a basebottom portion 111, a hollow portion 112 extending from the base bottomportion 111 and a seal portion 113, and the molded member 104 also has abase bottom portion 121, a hollow portion 122 and a seal portion 123.

As shown in FIG. 10, the base bottom portion 121 of the molded member104 is provided with two side slits 132L, 132R, a center slit 133,bridge portion 134L, 134R. In addition, the bridge portion 134R isprovided with a clip hole 135 for engaging a clip (not shown) therewith.

The center slit 133 is provided with a long slit part 137 as a firstslit part, and short slit parts 138 as second slit parts atsubstantially both ends (slightly on the inner side of both ends) of thelong slit part 137. The side slits 132L, 132R are provided with mainslit parts 139L, 139R, and extension slit parts 140L, 140R, 141L, 141Rextending from both end of the main slit parts. At the end sides of theextension slit parts 140L, 140R, 141L, 141R, substantially circular slitend portions 142 are formed.

The core mold in a molding device for molding the molded member 104 willnow be described on the basis of what are shown in FIG. 12. The coremold includes a center core 161, and a side core 162. The center core161 includes a center core body 163, and a center extension plate 164,and is held between an inside upper inner-mold (not shown) and an insidelower inner-mold 157. The length in the longitudinal direction of theweather strip 101 of the center core body 163 is set slightly smallerthan that of the thin portion 164A. At substantially both ends (on theslightly inner sides of both ends) of the thin portion 164A, orthogonaltransverse piece portions 165 as transverse piece portion of theinvention for forming the short slit parts 138 are formed in one bodywith the thin portion. The side core 162 includes two side core bodies166L, 166R, side extension plates 167L, 167R, and a connecting portion168. On a free end of the inside lower inner-mold 157, projections 169 afor forming the extension slit parts 140L, 140R, 141L, 141R, and a pin169 b for forming the clip hole 135 are provided in one body with thismold.

A method of manufacturing the weather strip 101 and the operation andeffects of the manufacturing of the weather strip will now be described.After the extruded member 102 is obtained, an end portion of the samemember is fitted by a predetermined length with the molding deviceopened into the longitudinal end portion of the side core body 166Lwhich does not face the center core 161, and set therein. The moldingdevice is then closed, and a material is injected into a cavity (notshown) and solidified. After the material is solidified, the molds areopened in order.

In order to open the molds, the side core 162 is slid with the weatherstrip 101, and the center core body 163 in the hollow portion is removedfrom the center slit 133 automatically with ease. During this time, theprojections 169 a and pin 169 b are also separated from the weatherstrip 101, so that clearances due to the extension slit parts 140L,140R, 141L, 141R, and the clip hole 135 come to be formed in the weatherstrip 101.

An operation for removing the molded member 104 from the side corebodies 166L, 166R is further carried out by the worker. The portion ofthe extruded member 102 which is in the vicinity of the joint portion ofthe molded member 104 is pulled to the left side of the drawing in thelongitudinal direction of the left side core body 166L. As a result, theweather strip 101 is slid comparatively easily with respect to the sidecore 162 owing to the elasticity of the molded member 104 itself andowing to the existence of the extension slit parts 140R, 141R. The leftside core body 166L is then removed in the same order as in the firstembodiment. The right side core body 166R is also thereafter removedfrom the weather strip 101 as the elasticity of the molded member 104and the provided extension slit parts 141L, 141R are utilized.

As described in detail above, the same operation and effects as in thefirst embodiment are displayed even in the second embodiment in whichthe molded member 104 is formed on an end portion of the weather strip101.

The present invention is not limited to what are described in thesemodes of embodiments, and the invention may also be practiced, forexample, in the following manner. Applied examples and modified exampleswhich are other than the examples referred to above, and which will notbe described in the following paragraphs, can also be practiced, ofcourse.

(a) In the above-described first and second modes of embodiments, thecenter slits 33, 133 and side slits 32L, 32R, 132L, 132R are provided onsubstantially the same line but these slits may not necessarily bearranged on the same line.

(b) In the above-described first and second modes of embodiments, thelength of the short slit parts 38, 138 are set substantially equal tothe width of the surface on the side of the hollow portion 22, 122 inthe base bottom portion 21, 121. The purpose is met as long as thecenter core body 63, 163 can be withdrawn from the center slit 33, 133,and the mentioned length is not limited to the mentioned level. Forexample, this length may be not smaller than ¾ of the width of thementioned surface, and also not smaller than ⅔ or not smaller than ½thereof.

(c) It is not necessary that the short slit parts 38, 138 be formed soas to cross the long slit part 137 at right angles thereto. For example,the short slit parts may be formed so as to diverge toward the sideslits.

(d) The short slit parts 38, 138 are provided at substantially both endportions in the longitudinal direction of the long slit part 37, 137.The purpose is met as long as the center core body 63, 163 is withdrawnfrom the center slit 33, 133. The positions in which the short slitparts are provided are not limited to the mentioned positions. Forexample, one short slit part may be provided in a position in thevicinity of the long slit part 37, 137 so that the center slit as awhole substantially has a shape of a cross or a shape of the letter “T”.

(e) The weather strip 1, 101 has a flexibility as mentioned above.Therefore, when the side core bodies 66L, 66R, 166L, 166R can bewithdrawn from the weather strip 1, 101, the length of the extensionslit parts 40L, 40R, 41L, 41R, 140L, 140R, 141L, 141R may be smallerthan that of fitting portions of the side core bodies 66L, 66R, 166L.

-   -   (f) All of the extension slit parts 40L, 40R, 41L, 41R, 140L,        140R, 141L, 141R may not have the same sizes.

(g) The extension slit parts 40L, 40R, 41L, 41R, 140L, 140R, 141L, 141Rare provided at both ends of the two side slits 32L, 32R, 132L, 132R,i.e., in four positions. These extension slit parts may not necessarilybe provided in four positions. For example, these slit parts may beprovided even in two positions on the side of the center slit 33, 133.

(h) The slit end portions 42, 142 may not be formed substantiallycircularly but may be formed so as to extend in the widthwise directionof the weather strip 1, 101 in the same manner as the short slit parts38, 138. This enables the side core bodies 66L, 66R, 166L, 166R to bewithdrawn more easily from the weather strip 1, 101.

(i) In the above-described first and second modes of embodiments, themolding device 51 is formed so that, when the molds are opened, the sidecore 62, 162 is slid with the weather strip 1, 101 with respect to theinside upper inner-mold 56 and inside lower inner-mold 157. However,conversely, the mold may be formed so that the center core 61, 161,inside upper inner-mold 56 and inside lower inner-mold 57, 157 are slidwith respect to the weather strip 1, 101 and side core 62, 162.

(j) A clip fixing hole may be provided in the bridge portion 34, 134L,134R, and, when occasion demands, an insert may be provided (buried).

(k) The side core 62, 162 may be divided into left and right portionswithout being connected together by the connecting portion 68, 168.

(l) The weather strips 1, 101 in the above-described first and secondmodes of embodiments are not provided with an insert but, even when theinsert is provided, any inconveniences may occur, of course.

(m) The order of removing the weather strip 1, 101 is not at all limitedto those in the above-described embodiments. Namely, the weather stripcan be removed in other order since the weather strip has apredetermined level of elasticity and owing to the existence of theextension slit parts 40L, 40R, 41L, 41R, 140L, 140R, 141L, 141R.

(n) The molded member can be applied to various kinds of shapes, such asa curved shape of a corner portion of a weather strip, and asubstantially linear shape of the weather strip irrespective of theconnecting condition of the molded member to (one end or both ends of)the extruded member.

1. A manufacturing method of a weather strip, wherein said weather stripincludes a molded member provided with a base bottom portion, and a sealportion in which a hollow portion is formed, projecting from said basebottom portion, and said weather strip is formed in a cavity of amolding device which is provided with at least a core mold for formingsaid hollow portion, said core mold including a center core having acenter core body and a center extension plate extending from said centercore body, and a side core having a pair of side core bodies adjacentlyprovided at both sides of said center core in a longitudinal directionof said weather strip, and side extension plates extending from saidside core bodies; said manufacturing method comprising the steps of:injecting an elastic material in a plasticized state being injected intothe cavity, so that the cavity is filled with said elastic material;solidifying said elastic material, wherein at least three slits arrangedin a longitudinal direction of said base bottom portion are formed onsaid base bottom portion, and bridge portions are formed betweenadjacent ones of said slits; removing said core mold from said slits toobtain said molded member in which said hollow portion is formed,wherein said slits includes a center slit from which said center corebody is withdrawn, and a pair of side slits from which said side corebodies are withdrawn; and said center slit includes a first slit parthaving a length substantially equal to a length of center core body inthe longitudinal direction of said weather strip, and second slit partsextending in a direction in which the second slit parts intersect withthe first slit part; wherein said center core body is withdrawn fromsaid center slit and thereafter said side core bodies are with drawnfrom said side slits, when said core mold is removed.
 2. A method ofmanufacturing a weather strip according to claim 1, wherein said sideextension plates are joined together with a connecting portion, and whensaid core mold is removed by sliding said side cores in an extendingdirection of said side extension plate, said side core bodies areseparated relatively from said center core body, and said center corebody is withdrawn from said hollow portion of said molded member.
 3. Amethod of manufacturing a weather strip according to claim 1, whereineach of said side slits includes: a main slit part formed by said sideextension plates, and extension slit parts provided so as to extend fromends of said main slit part in the longitudinal direction of saidweather strip and formed by a mold part different from said sideextension plates.
 4. A method of manufacturing weather strips accordingto claim 3, wherein said mold part for forming the extension slit partsis separated relatively from said side core bodies at the same time thatsaid center core body is separated relatively from said side core bodiesand extracted when said molding device is opened.
 5. A method ofmanufacturing a weather strip according to claim 3, wherein saidextension slit parts of said side slits are formed on both ends of saidmain slit part, said molded member is set relatively movable when saidside core bodies are withdrawn from said side slits, so that said sideextension plates are made to be put into one end side extension slitpart.
 6. A method of manufacturing a weather strip according to claim 1,wherein said center slit is formed by said center extension plate.
 7. Amethod of manufacturing a weather strip according to claim 1, whereinsaid second slit parts of said center slit are formed substantially atboth end portions of said first slit part thereof so as to intersectwith said first slit part substantially at right angle, and so as tohave a length substantially equal to a width of a surface of the centercore body which is located on a side of said base bottom portion.
 8. Amethod of manufacturing a weather strip according to claim 1, whereinsaid molded member is a member fitted in a corner portion of a doorsash, said at least three slits are formed in one side of said cornerportion, in an angular section of the corner portion, and in a sectionof said base bottom portion which correspond to another side of saidcorner portion.
 9. A method of manufacturing a weather strip accordingto claim 1, wherein said molded member is made so as to connect bothends of a single extruded member that is formed separately, or ends of aplurality of extruded members together.
 10. A method of manufacturingweather strip according to claim 1, wherein said molded member is formedso as to be connected to one end of said separately formed extrudedmember.
 11. A weather strip comprising: a molded member including a basebottom portion, and a seal portion in which a hollow portion is formed,projecting from said base bottom portion, said base bottom portion beingprovided with at least three slits including a center slit, and two sideslits formed on both sides of said center slit, so that bridge portionsare formed between adjacent ones of said slits, and said center slitbeing provided with a first slit part, and second slit parts formedsubstantially at both ends of the first slit part so that said secondslit parts intersect with the first slit part.
 12. A weather stripaccording to claim 11, wherein said molded member has a curved shape sothat said molded member is fitted in an opening portion of a vehicle ora corner portion of a circumference of a door, said center slit as awhole is formed substantially in an H-shape or substantially in aU-shape since said second slit parts are formed so as to intersect withsaid first slit part substantially at right.
 13. A weather stripaccording to claim 11, wherein: said molded member is formedsubstantially linearly, said center slit as a whole is formedsubstantially in an H-shape or substantially in a U-shape since saidsecond slit parts are formed so as to intersect with said first slitpart substantially at right angle.
 14. A weather strip according toclaim 11, wherein both ends of single extruded member is separatelyformed, or end portions of a plurality of extruded members are connectedto both sides of said molded member.
 15. A weather strip according toclaim 11, wherein said molded member is connected to the end portion ofthe separately formed extruded member to form a terminal portion of theweather strip.
 16. A molding device comprising: a core mold for forminga molded member of a weather strip including a base bottom portion, anda seal portion projecting from said base bottom portion and forming ahollow portion therein are installed, said core mold being providedwith: a center core having a center core body for forming said hollowportion, and a center extension plate extending from said center corefor forming a center slit in said base bottom portion, and a side coreprovided with a pair of side core bodies, which are connected to bothsides of said center core in a longitudinal direction of said weatherstrip, side extension plates extending from said side core bodies forforming side slits in said base bottom portion, and a connecting portionfor connecting said side extension plates; wherein transverse pieceportions extending in a direction intersecting with said centerextension plate are provided at both ends of said center extension platein the longitudinal direction of said weather strip, contacting withsaid center core body.
 17. A molding device according to claim 16,wherein projections for elongating said side slits are proved so as tobe close contact with end portions of said side extension plates in thelongitudinal direction of said weather strip and said side core bodies,said projections being provided in a mold part different from said sidecores.